Drug Interaction Report

GENERALLY AVOID: Topically administered doxepin may be systemically absorbed and produce plasma levels that approach therapeutic ranges. While drug interaction studies have not been conducted with topical doxepin, coadministration of oral tricyclic antidepressants with monoamine oxidase inhibitors (MAOIs) has been associated with significant adverse reactions including nausea, vomiting, flushing, dizziness, tremor, myoclonus, rigidity, diaphoresis, hyperthermia, autonomic instability, hypertensive crisis, disseminated intravascular coagulation, severe convulsive seizures, coma, and death. The exact mechanism is unknown but may be related to excessive serotonergic activity in the CNS (i.e., serotonin syndrome).

MANAGEMENT: As with oral doxepin and other tricyclic antidepressants, topical doxepin should not be used concurrently with MAOIs or other agents that possess MAOI activity (e.g., furazolidone, methylene blue, procarbazine). At least 14 days should elapse between discontinuation of MAOI therapy and initiation of treatment with topical doxepin, and vice versa.